Radiation induced crosslinking of polytetrafluoroethylene

Electron beam irradiation of polytetrafluoroethylene in vacuum at elevated temperature: An infrared spectroscopic study

“…3 Recently, it was found that PTFE is crosslinked by ionizing radiation under specific conditions: irradiation in an oxygen-free atmosphere at approximately 340°C; that is, a temperature just above the melting point of PTFE. 4 -10 This crosslinking was assumed because the yield strength and modulus increase, 5 the heat of crystallization decreases with increasing radiation dose, 5 unirradiated white-colored PTFE sheets become transparent due to reduced crystallinity, 7 the mode of molecular motions changes, 6,8 and the radiation resistance is much improved. 6,7 We investigated the irradiation of PTFE under the aforementioned conditions using the electron beam facility in our institute.…”

Radiation-induced free radicals and their behaviour in crosslinked polytetrafluoroethylene (PTFE)

“…8 The crosslinking was con®rmed as follows: the yield strength and Young's modulus improved, 2,4,6,7 the white colour becomes transparent because of a decrease of crystallites, 2,4,6,7,9 the radiation resistance is much improved, 6,7,9 and the crosslinking sites are clearly detected by 19 F high speed MAS NMR spectroscopy. 10 The nature of the transition and relaxation related to the molecular motion is in¯uenced to a large extent by crosslinking.…”

?-Irradiated poly(tetrafluoroethylene) particle-filled low-density polyethylene. I. Effect of silane coupling agents on mechanical, thermal, and morphological properties

“…[17][18][19][20][21][22] However, high-energy radiation under vacuum showed the characteristics of olefin formation in the polymer chain and was responsible for the possible branching or crosslinking reactions. 23 The changes in thermal expansion coefficient, 24 thermal conductivity, 25 and dielectric properties 26 of PTFE were also studied when PTFE was exposed to ␥-irradiation.…”